21311221112 has 8 divisors (see below), whose sum is σ = 39958539600. Its totient is φ = 10655610552.

The previous prime is 21311221103. The next prime is 21311221153. The reversal of 21311221112 is 21112211312.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1331951312 + ... + 1331951327.

It is an arithmetic number, because the mean of its divisors is an integer number (4994817450).

Almost surely, 2^21311221112 is an apocalyptic number.

It is an amenable number.

21311221112 is a deficient number, since it is larger than the sum of its proper divisors (18647318488).

21311221112 is a wasteful number, since it uses less digits than its factorization.

21311221112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2663902645 (or 2663902641 counting only the distinct ones).

The product of its digits is 48, while the sum is 17.

Adding to 21311221112 its reverse (21112211312), we get a palindrome (42423432424).

The spelling of 21311221112 in words is "twenty-one billion, three hundred eleven million, two hundred twenty-one thousand, one hundred twelve".